The subject application discloses improved tufting apparatus which utilizes concepts from tufting procedures which have become known as the "Spanel Tufting System." Generally, the system utilizes pneumatic means to transport yarn to a tufting station (either in metered lengths of an unsevered yarn strand or in discrete bits), after which time the yarn is tufted, preferably by the use of multiple needles, into a backing layer to form a tufted product.
The present invention discloses improvements to the embodiments in the early Spanel patents, i.e., U.S. Pat. No. 3,554,147 which issued to Abram N. Spanel and George J. Brennan on Jan. 12, 1971 and U.S. Pat. No. Re 27,165 which issued Aug. 10, 1971 to Aabram N. Spanel and Lloyd E. Barton.
The aforementioned U.S. Pat. No. Re 27,165 discloses a pneumatic yarn transport system in which yarn strands and/or discrete bits of yarn are transported pneumatically to a tufting station where they are applied by tufting elements to a backing layer. Multicolor selection of the yarn bits is enabled by a shifting magazine arrangement, which provides yarn of various colors to each of the guide tubes through which yarn is transported to the tufting elements.
The aforementioned U.S. Pat. No. 3,554,157 describes an alternative system of U.S. Pat. No. Re 27,165 and provides for the simultaneous selection of bit-lengths of yarn of various colors for each tufting cycle at each individual tufting station. In place of the shifting magazine structure of U.S. Pat. No. Re 27,165, there is utilized a collator structure in which individual channels transport yarn into a common passageway adjacent the tufting station. The capability of severing a bit-length of yarn before, during or after threading of the tufting element and before or during actual tufting is provided. Since the severing function in the preferred embodiment takes place in close proximity to the tufting station and after a selected yarn strand has been fed into the common passageway, U.S. Pat. No. 3,554,147 discloses a pullback system to remove the yarn strand from the common passageway once a yarn bit has been severed therefrom.
In addition to the above Spanel patents, copending Spanel application Ser. No. 419,417 discloses a tufting device similar in some respects to those disclosed in the Spanel/Barton and Spanel/Brennan cases, but which utilizes a cutting arrangement employing an axially reciprocable passageway section to provide access for yarn severing means to sever the yarn into selectively sized discrete yarn bits.
In addition, copending Spanel application Ser. No. 240,119 discloses modified tufting apparatus which provides multi-color selection and utilizes a reciprocable threader tube to place yarn in the eye of a needle and retract to leave the yarn deposited therein. Pneumatic means supplement the yarn transportation system.
Finally, Spanel application Ser. No. 474,265 and Ser. No. 474,266 have been filed concurrently herewith and disclose inventions which may be used in conjunction with the subject disclosure. For example, the clamping means of Ser. No. 474,266 may be utilized with either of the principal embodiments disclosed herein and the yarn metering system of this application may be used in conjunction with the threader tube assembly of Ser. No. 474,265.
While all of the above Spanel patents and pending applications have merit and involve principles which are presently utilized, nevertheless, the subject invention provides apparatus which, for production purposes and operational efficiency, is far superior to that of the preexisting disclosures.